This invention relates to skeleton or transfer wheels of the general type used in high speed, multi-station printing presses, and more specifically to a new and improved method and apparatus for attaching an anti-smear fabric web to such wheels.
To my U.S. Pat. No. 3,791,644 there is disclosed a skeleton wheel for use in a printing press to reduce marking and smearing of the printed surface of a sheet during conveying of the sheet between processing stations in the press. My U.S. Pat. No. 4,402,267 is directed to an improvement of the invention disclosed in my earlier patent, and specifically to a method and apparatus including the attachment of an anti-smear fabric to the support surface of a skeleton wheel.
As disclosed in my U.S. Pat. No. 4,402,267, for proper operation, the anti-smear fabric must be loosely attached to the support surface of the skeleton wheel to permit and accommodate slight relative movement between the fabric covering and the wheel support surface when the printed sheet is supported and transferred by the wheel. As also disclosed in that patent, the fabric covering is attached to the skeleton wheel by fastening strips, such as double sided adhesive strips or fastening strips made under the trademark VELCRO, extending along the axial width of the wheel and disposed along in-turned flanges formed at the leading and trailing edges of the cylindrical supporting wheel surface.
While the method and apparatus disclosed in my aforementioned U.S. Pat. No. 4,402,267 has been highly successful in use, it has been found that some printed sheet marking and smearing may occur in the immediate area of the leading and trailing edges of the wheel support surface, and particularly in the area of the leading edge. It has now been determined that such marking and smearing is caused principally by the manner in which the axial ends of the fabric are fastened to the wheel.
With the use of fastening strips formed on in-turned flanges, as disclosed in my U.S. Pat. No. 4,402,267, the fabric extends over the leading and trailing edges of the wheel support surface in a generally taught condition, thereby restricting relative movement of the fabric in the area of the leading and trailing edges. Due to this taught condition, marking and marring of freshly printed sheets has occurred.
The present invention solves the problem of marking and marring freshly printed sheets in the area of the leading and trailing edges of the wheel support surface by providing a new and improved method and apparatus for attaching the fabric to the wheel.